One of the first steps in hydrocarbon exploration is to generate a consistent stratigraphic framework by interpretation of the post stack processed seismic volume to be explored. This includes the identification of depositionally equivalent beds.
In some structurally complex regions, such as deep water depositional environments, this first step may prove challenging because of the structural complexity which can cause differential deposition (i.e., varying thickness) and stratigraphic unconformities or discontinuities between beds with common times of deposition. By way of example, where a seismic volume includes two or more separate basins, beds and/or horizons bounding the beds within the separate basins may have been deposited at the same time, but correlation between such beds may be difficult to determine because of the unconformities, discontinuities (missing sections) or variable thicknesses between the basins.
Conventional techniques exist for analyzing seismic data and correlating between (i.e., tieing) separate basins. These techniques include identifying and correlating features such as surfaces (beds) and events located in the separate basins that have common times of deposition. However, the accuracy of these techniques in correlating stratigraphically equivalent events may be incorrect and/or lacking in some instances.
The definitive methodology for determining an accurate tie between basins is drilling a well in each basin, logging the well and sampling the data from the well bore. This is time intensive and expensive in terms of equipment and man hours.